Conventional strap bindings for snowboards include a highback for supporting the calf region of the snowboarder. This highback structure effectively locks out the forward extension movement of the ankle, thus allowing the forces from the rider's legs to transfer directly into the heel side edge of the snowboard. Without this highback structure, the rider's leg muscles would have to lock out the ankle in order to "tip" the board onto its heel side edge in order to make a heel side turn.
Snowboard boots generally come in two varieties; soft boots and hard boots. Hard boots are generally limited to use in combination with plate bindings. Soft boots are widely used with strap bindings and they are very popular with snowboarders since they are easy to fit and are comfortable both on and off the snowboard.
With the advent of step-in bindings for snowboards, the external highback structure of the binding is eliminated. Unfortunately, the ankle support capability of conventional soft style snowboard boots is insufficient, in most cases, to provide effective support to the rider's ankle and lock out the forward extension of the rider's ankle movement. The ability of a snowboard boot and/or snowboard binding to effectively lock out a specific range of movement of the ankle is critical to the positive feel and turning control of the snowboard.
Accordingly, it would be desirable to internally reinforce a soft style snowboard boot so that it could provide the necessary ankle movement lock out and support functions associated with conventional highback strap bindings. Further, it would be desirable to provided such a reinforced soft boot which also retains the comfort and fit features associated with conventional soft style snowboard boots. As can be readily appreciated by anyone of ordinary kill in the art, the above noted design considerations are in conflict with each other.
Others have proposed to solve this problem in various ways. For example, published European Patent application EP 0 646 334 A1 discloses a soft boot insert which includes a heel cup/foot bed portion which is pivotally connected to an upper highback portion. Straps are connected between the highback portion to the lower foot bed portion adjacent both sides of the ball of the foot. A shortening adjustment of the straps provides a change in the forward lean of the boot insert by pulling the upper highback portion forwardly toward the toe end of the heel cup foot bed portion of the boot insert.
Blax of Germany is currently selling a version of this type of highback soft boot insert under the trade name of I-SPINE. The Blax system utilizes a single direction tension adjustment via a ladder strap that runs vertically up the back of the ankle.
K-2 Corporation of Vashon, Wash. currently markets a product that utilizes a non-adjustable reinforcement in the construction of the boot. This is little more than the typical thermal formed heel "counter" material used in shoe making to make the heel area ridged and not wrinkle.
The ski industry has proposed and produced many solutions to this problem. However, none of these solutions are appropriate for snowboarding applications since they also require locking out or restraint of the lateral ankle movement. While locking out the lateral ankle movement is essential for skiing, it is detrimental for snowboarding since lateral movement of the ankle is essential for performing even the most fundamental snowboarding maneuvers.
The present invention overcomes the above noted problems of the prior art by relocating the calf supporting highback structure of conventional strap bindings to the inside of the soft style snowboard boot. Just as in the case with conventional high back strap bindings, the same functional criteria apply for the improved reinforced snowboard boot of the present invention, in that the internal boot support structure must be able to lock out a specific range of movement of the ankle in such a manner that forces exerted by the leg will be efficiently transferred through the matrix of boot, binding and board so that turn initiating leg movement results in a more positive and direct rotation of the snow board along its lengthwise axis.